Roller boring drill



Dec. 15, 1936. F. 1.. SCOTT ROLLER BORING DRILL Flleci April 22, 1935 3 W. Z I v lll'l'llllll'll 8 Fig. 3

Patented Dec. 15, 1936 PATENT OFFICE v 2.064.213 ROLLER BORING DRILL Floyd L. Scott, Houston, Tex., assignor to Hughes T0010 Texas ompany, Houston, Tex, a. corporation of Application April 22, 1935. Serial No. 17,684

10 Claims.

My invention relates to roller boring drills for 1.1;: in drilling deep wells for oil, gas, and the Objects of the invention are as follows:

(1) To provide a drill with a plurality of rolling cutters thereon, the body of which is of comparatively light weight.

(2) To provide a drill having a central sup-""- port for the inner ends of a plurality of bearing pins for the cutters.

(3) To form a drill of symmetrical structure, in which the cutters and shafts are removably mounted for assembly in-such a manner that the parts subject to wear are easily replaceable.

(4) To secure the cutters upon the bearing pins by anti-friction means easily removed when the bit is disassembled.

In the drawing Fig. 1 is a central longitudinal section through a well drill equipped according to my invention,

Fig, 2-is a similar section taken at 90 from that shown in Fig. 1.

Fig. 3 is a transverse section on 'the plane 33 of Fig. 1.

Fig. 4 is a detail of the lower end of a cutter support.

The drill head I is of a generally cylindrical form with longitudinal flutes or grooves 2 therein. Between said flutes are four channels 22 having side walls 3 thereon extending longitudinally of the head. The head has an upper tapered shank 4 for attachment to the drill collar, not shown.

The lower end of the head has four recesses or pockets formed therein. Two opposite recesses 5 open outwardly and downwardly to receive cutters B therein. Two other opposed recesses 1 open in a similar manner tosreceive cutters 8 which are rotatably mounted therein. There is a central post or support 9 between these four cutter pockets which has openings I0 to receive cutterv pins 'or shafts ll therein. It has also two opposite recesses l2 to support the inner ends of cutter shafts l3.

The head has a central fluid channel H which is reduced in diameter at l5 between the cutter pockets. This allows free flow of flushingfluid and materially reduces the weight of the bit head. Openings I6 lead from the lower end of the large passage to the cutter pockets 1, and

' openings l'l lead to the pockets 5. I

The cutters 6 may be cylindrical in shape and mounted on the bearing pins II which are also cylindrical in form, wltha radial flange 18 to space apart the two rows of roller bearings strengthening the pin support,

IS. The inner wall of I each recess 5 has a boss 20 around the cutter pin receiving opening l0. forming a portion of the cutter bearing and The outer end of each bearing pin H is supported ina removable arm 2| which has its upper portion, above the outer side of the cutter recess 5, flattened to fit within the longitudinal channel 22, one of which is formed between each of the side walls 3. A transverse pin 23 extending through the walls and arm secures the said arm pivotally in the channel. The arm is tapered in width upwardly and outwardly on its inner side and the upper end is bent inwardly at 24, adjacent a shoulder 25 in said channel. A set screw 26 through the bent end bears against the shoulder 25 to force the upper end of the arm outwardly as desired. The lower end of the arm 2| is widened laterally to form a head 21 partly closing the outer side of the cutter recess 5. The cutter pin II is received within. a recess 28 in the lower inner face of the arm.

The cutters 8 are mounted-on shafts or pins l3, the outer ends ofwhich are supported in openings 29 in the lower ends of arms 2|, similar to arms 2| just described. The central portion of the shaft I3 is enlarged to support the cutters, and the cutters 8 have antifriction bearings, including a row of rollers 30 and a row of balls 3! set in races in the shaft and cutter. The balls are inserted into their racew'ays when the cutters are on the shafts, through diagonal passages 32 in the shafts l3, said openings being then closed by a plug 33. The inner end of the pin or shaft l3 has an offset reduced member 34 fitting in the recess 12 which prevents rotation of the shaft. The cutters 8 have bearing thrust washers 35 on the inner walls of the recesses I and the cutters 6 having similar washers 36 on the outer wall formed by the head 21 of the supporting arm.

It will be noted that the cutter shafts II are inclined downwardly and outwardly while the cutter shafts l3 are inclined upwardly and outwardly, thus adapting the cutters together to cut the full bottom of the hole, except for a small central portion indicated at 31 in Fig. 2. This uncut portion is broken off by the vibration of the drill and washed away by the flushing mud.

In a drill constructed as described, the cutters may be mounted upon their shafts and inserted in position with their shafts fitting in the recesses in the central support 9. The

cutters a is locked on their pins by the balls 3|, and the plugs ll filling the openings through which they were inserted are held against re-. moval by the walls of the openings 20 in the supporting arms. The arms are inserted over the ends of the cutter shafts and are supported by the pins 23 inthe head. The cutter shafts of material. The parts subject to wear are detachable and may be sent to the shop for repair without including the bit head.

What I claim as new is:

1. A well drill including a body, opposed radial channels longitudinally thereof, a plurality of outwardly and downwardly opening pockets in the lower end of said body, a cenia'lal post on said body between said pockets, cutter shafts in said pockets, the inner ends thereof being supported in said post, supporting arms pivotally supported in said channels, means to limit pivotal movement of said arms, heads on the lower ends of said arms forming an outer wall for each of said pockets, supports in said heads for said shafts and cutters rotatable on said shafts.

2. A well drill including a body, four uniformly spaced channels extending longitudinally on said body, four pockets formed in the forward end of said body, one below each of said channels, arms pivotally mounted in said channels, means to limit pivotal movement of saidarms, heads on said arms closing the outer sides of said pockets, a central integral post on said body between said pockets, a cutter shaft in each of said pockets supported at one end in said post and at its outer end in one of said heads, bearings on said shafts and cutters on said bearings, said cutters and shafts being removable with said arms from said body.

3. A well drill constructed as set out in claim 2 which has a comparatively large water passage axially of said body and post.

4. A well drill as set out in claim 2 in which there are branch openings from said passage to each of said pockets.

'5. A well drill includinga drill body, a central integral post extending forwardly from the lower .ends in the other pair of pockets and extending downwardly and outwardly, removable supports in said body for the outer ends of said shafts, bearings on said shafts in said pockets and cutters rotatable on said bearings.

6. A drill bit construction as recited in claim 5 in which the removable supports hold said cutter shafts in position in said post and are adjustable to exert pressure longitudinally of said shafts.

7. A drill bit construction as recited in claim 5 in which the said body is made light in weight by a comparatively large axial water course extending through said body and post.

8. A drill bit including a body, a forwardly projecting post on said body, oppositely disposed pairs of pockets in said body at the sides of said post, cutter shafts in said pockets supported in saidpost at one of their ends, and remoyable supportsin said head for the other ends of said shafts said supports being radially adjustable to clamp said shafts in said head, means to prevent rotation of said shafts, and cutters on said shafts.

9. A drill bit including a body, a forwardly projecting post on said body, oppositely disposed pairs of pockets in said body at the sides of said post, cutter shafts in said pockets supported in said post at one of their ends, and removable supports in said head for the other ends of said shafts said supports being radially adjustable to clamp said shafts in said head, means .to prevent rotation of said shafts, and cutters on said shafts, the cutters in one pair of pockets being positioned to cut the outer portion of the hole and the other pair of cutters positioned to cut the inner portion of the hole.

10. A drill bit includinga body, a tubular post axially of said body, two pairs of pockets in said body at the sides of said post, cutter shafts in said pockets supported at one of theirends in said post, laterally adjustable supports in said head at the outer ends of said shafts and cutters on said shafts.

FLOYD L. SCO'I'I. 

